Merge pull request #2323 from johnplatts:hwy_test_enh_090524

PiperOrigin-RevId: 681467921

CMakeLists.txt

@@ -87,6 +87,12 @@ set(HWY_ENABLE_EXAMPLES ON CACHE BOOL "Build examples")
 set(HWY_ENABLE_INSTALL ON CACHE BOOL "Install library")
 set(HWY_ENABLE_TESTS ON CACHE BOOL "Enable HWY tests")
 
+if (MSVC)
+set(HWY_TEST_STANDALONE ON CACHE BOOL "Disable use of googletest")
+else()
+set(HWY_TEST_STANDALONE OFF CACHE BOOL "Disable use of googletest")
+endif()
+
 if (NOT DEFINED CMAKE_CXX_STANDARD)
   if ("cxx_std_17" IN_LIST CMAKE_CXX_COMPILE_FEATURES)
     set(HWY_CXX_STD_TGT_COMPILE_FEATURE cxx_std_17)
@@ -579,6 +585,15 @@ if (HWY_ENABLE_CONTRIB)
 list(APPEND HWY_PC_FILES libhwy-contrib.pc)
 endif()  # HWY_ENABLE_CONTRIB
 if (HWY_ENABLE_TESTS)
+
+if (HWY_TEST_STANDALONE)
+  set(HWY_PC_HWY_TEST_REQUIRES "")
+  set(HWY_PC_HWY_TEST_CFLAGS "-DHWY_TEST_STANDALONE=1")
+else()
+  set(HWY_PC_HWY_TEST_REQUIRES "gtest")
+  set(HWY_PC_HWY_TEST_CFLAGS "")
+endif()
+
 list(APPEND HWY_PC_FILES libhwy-test.pc)
 endif()  # HWY_ENABLE_TESTS
 foreach (pc ${HWY_PC_FILES})
@@ -628,6 +643,8 @@ enable_testing()
 include(GoogleTest)
 
 set(HWY_SYSTEM_GTEST OFF CACHE BOOL "Use pre-installed googletest?")
+
+if(NOT HWY_TEST_STANDALONE)
 if(HWY_SYSTEM_GTEST)
 find_package(GTest REQUIRED)
 else()
@@ -656,6 +673,7 @@ add_subdirectory(${CMAKE_CURRENT_BINARY_DIR}/googletest-src
                  ${CMAKE_CURRENT_BINARY_DIR}/googletest-build
                  EXCLUDE_FROM_ALL)
 endif()  # HWY_SYSTEM_GTEST
+endif()  # HWY_TEST_STANDALONE
 
 set(HWY_TEST_FILES
   hwy/contrib/algo/copy_test.cc
@@ -745,15 +763,19 @@ list(APPEND HWY_TEST_FILES
 )
 endif()  # HWY_ENABLE_CONTRIB
 
-if(HWY_SYSTEM_GTEST)
-  if (CMAKE_VERSION VERSION_LESS 3.20)
-    set(HWY_GTEST_LIBS GTest::GTest GTest::Main)
+if(HWY_TEST_STANDALONE)
+  set(HWY_GTEST_LIBS "")
+else()
+  if(HWY_SYSTEM_GTEST)
+    if (CMAKE_VERSION VERSION_LESS 3.20)
+      set(HWY_GTEST_LIBS GTest::GTest GTest::Main)
+    else()
+      set(HWY_GTEST_LIBS GTest::gtest GTest::gtest_main)
+    endif()
   else()
-    set(HWY_GTEST_LIBS GTest::gtest GTest::gtest_main)
+    set(HWY_GTEST_LIBS gtest gtest_main)
   endif()
-else()
-  set(HWY_GTEST_LIBS gtest gtest_main)
-endif()
+endif()  # HWY_TEST_STANDALONE
 
 file(MAKE_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/tests)
 foreach (TESTFILE IN LISTS HWY_TEST_FILES)
@@ -766,6 +788,9 @@ foreach (TESTFILE IN LISTS HWY_TEST_FILES)
   # cause compile errors because only one may be set, and other CMakeLists.txt
   # that include us may set them.
   target_compile_options(${TESTNAME} PRIVATE -DHWY_IS_TEST=1)
+  if(HWY_TEST_STANDALONE)
+    target_compile_options(${TESTNAME} PRIVATE -DHWY_TEST_STANDALONE=1)
+  endif()
   target_compile_features(${TESTNAME} PRIVATE ${HWY_CXX_STD_TGT_COMPILE_FEATURE})
 
   target_link_libraries(${TESTNAME} PRIVATE ${HWY_TEST_LIBS} ${HWY_GTEST_LIBS})